<!DOCTYPE html>
<html>
<head lang="en">
    <meta charset="UTF-8">
    <title>盒子模型的应用</title>
    <link href="style.css" type="text/css" rel="stylesheet">
</head>
<body>
  <div class="top">
    <div class="top_content"></div>
  </div>
  <div class="body">
    <div class="body_img"></div>
    <div class="body_content">
        <div class="body_no"></div>
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  <div class="footing">
      <div class="footing_content"></div>
      <div class="footing_subnav"></div>
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</body>
</html>